An Australian court heard Adam Britton filmed himself torturing dozens of dogs until almost all died.
He would then post videos of the incidents online, where he also accessed child abuse material.
A leading zoologist who has worked on BBC and National Geographic productions, Mr Britton will be sentenced at a later date.
At a hearing in the Northern Territory (NT) Supreme Court on Monday, prosecutors laid out the case against him.
Much of the details of Mr Britton’s crimes are too graphic to publish, and so “grotesque” the judge warned people to leave the courtroom.
I am questioning the word “weird” and “sexuality”
Sexual exploitation of dogs and killing them is not weird sexuality, its a psychopathic behavior. It’s clearly someone who want to do it to kids but cannot so they did it to animals…